Automated bag on a roll

ABSTRACT

An automated bag is provided that is made from a plastic film, with a filling opening, a front wall, a back wall and a back wall extended in the area of the filling opening to form a bag flap, wherein the front wall and the back wall are welded together on their longitudinal sides to form side walls and on a transverse side opposite the filling opening to form a bottom seam, wherein the bag has an extension projecting beyond the bottom seam and at least the bag flap is connected removably with a bag flap of an additional bag and the extension is connected continuously with the bags.

This nonprovisional application claims priority under 35 U.S.C. § 119(a) to German Patent Application No. DE202007009540 US1, which was filed in Germany on Jul. 6, 2007, and which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a bag made of a plastic film, especially an automated bag, with a filling opening, a front wall, a rear wall and a rear wall extended in the area of the filling opening to form a bag flap, wherein the front wall and the back wall are welded together on their longitudinal sides to form side walls and on a transverse side positioned opposite the filling opening to form a bottom seam.

2. Description of the Background Art

In the continuous manufacturing of bags it is generally known to combine a predetermined number of bags, for example a quantity of approximately 500 bags, into so-called bag stacks in a collecting device. A suitable collecting device, for example, is a pin stacker collecting device with a pin stacker chain conveyor moving in a horizontal direction, which takes up the separated bags on stacking pins. The stacking openings are punched into each bag, with the distance between the openings corresponding to the distances of the stacking pins on the pin stack chain conveyor. In producing the bag stack it is also known to fix these with a wire clip (wicket) in such a manner that the arms of the wicket are passed through the stack openings in the flap part of the bags. For this purpose either the bag stack is lifted from the stacking pins of the pin stack conveyor device and placed with the bags now lying loosely against one another on the arms of the wicket, or the arms of the wicket are inserted into groove-like recesses in the stacking pins of the pin stack chain conveyor and in this way the respective bag stack is removed. For stabilizing the bag stack and for protection against damage by the ends of the wicket in the joint packing of several bag stacks, these are placed between a front and a rear cover sheet and additionally secured by retaining discs or rubber stoppers placed on the arms of the wicket. All these processes are generally carried out manually by an operator and are described in EP 1 036 741 B1.

Aside from the considerable expense for auxiliary materials, conventional bag stackers are quite difficult to pack and transport because of the awkward wicket.

Also during a packaging process, i.e., during the filling of a bag with a product, for example with a feminine hygiene article, diapers, bread or the like, considerable drawbacks occur. In the filling process the wicket passed through the punched-out stacking opening serves to fasten the stack of bags to the packing machine, for example an automatic packaging machine. Since during the packaging process the product placed inside, for example a loaf of bread, is pulled along together with the bag surrounding it, this means that the filled bag is transported in a linear manner to a closure device. Not only does the linear pulling of the bag with the product packed in require a bag of accurate dimensions, but also a sudden tearing of the starter cut area usually located between the stack openings and the front edge of the flap takes place in this process. The starter cut edge area of the flap not only gives an unattractive appearance to the bag as a whole, but also the bag flap surface is no longer immediately suitable for reliable fastening with closure elements, such as adhesive labels or the like and/or as a surface for imprinting or for receiving instructions.

Finally, after filling all bags, if desired the wickets must be transported back to the manufacturer, sorted by size and optionally prepared for reuse.

To overcome these drawbacks, it is suggested in EP 1 036 741 B1 that the starter cut section be formed as a tearable perforation by perforation lines each running at an angle to the filling opening and delimiting a corner section, and that at least one blocking site blocking the bags in the stack with one another is present in each corner section. A drawback of this is that the bag stacks must still be positioned by hand in a limited number, and the perforated, blocked marginal area remaining in the machine must be removed.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to create a stack of bags of the that do not require expensive auxiliaries, and in addition distinctly increases the performance capacity of a packing machine and can be obtained with minimal construction and material costs.

This object is achieved in an embodiment, in that the bag has an extension projecting out beyond the bottom seam and that at least the bag flap is connected removably with a bag flap of an additional bag and the extension is connected continuously and removably with the bags. As a result of the design of the bags in accordance with the invention, or more specifically the bags connected together, the possibility is now created of placing an automated bag as roll goods, for example in a packaging machine.

Through a first removable connection between two adjacent bags in the area of the bag flap and a second connection of the bag through the extension in the area of the bottom seam in accordance with the invention it is possible to supply a bag that can be rolled up. In this process the continuous extension, i.e., extending over all of the bags connected to one another, at the lower end of the bag in the area of the bottom seam serves as a retaining or winding strip. The retaining or winding strip is connected removably with the bags, which can be accomplished for example by means of a perforation that is introduced into the bag together with the production of the weld of the bottom seam. Thus the retaining or winding strip on one hand serves as a connecting link between the bags, and on the other hand a continuous plastic roller strip is supplied for reliable conveyance of the bag in the packaging machine. Before, during or after the filling of the bag the retaining or winding strip is removed from the bag and can be disposed of separately; if the retaining or winding strip is again rolled up within the packing machine, easy space-saving disposal is made possible. The removable connection in the area of the bag flap, exactly like the extension in the area of the bottom seam, serves as a retaining or winding strip, wherein the bag flap is connected permanently to the bag as a functional element, wherein the bag flap is preferably formed as part of the back wall of the bag. For reliable rolling up of the bags and guidance of the bags in the machine, the bag flaps, arranged adjacent to one another, are removably connected with one another.

The bag flaps can be connected over a perforation, so that easy separation of the bags in the packaging machine can take place. In this process, on one hand the requirement is imposed that the perforation must be firm enough to permit winding and transport through the machine, and on the other hand the perforation must be easily removable to permit problem-free separation of the individual bags in the packing machine.

Through the use of rolled bags in accordance with the invention in packing machines, the number of bags available in the machine is distinctly increased. If about 500 bags are present in a bag stack known according to the state of the art, by rolling up the bags into a bag roll it is possible, depending on the bag size, diameter of the roll and thickness of the film, to roll up a much larger number of bags on a roller or in themselves. This in turn offers the advantage that an operator of the machine can spend less time for resupplying the packing machine, which in turn positively affects the nonproductive time, especially the resupply time of the machines.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

FIG. 1 illustrates a partially unwound bag roll as well as a bag in a longitudinal section, as a three-dimensional representation, according to an embodiment; and

FIG. 2 illustrates part of a folded bag in cross-section and in a three-dimensional representation.

DETAILED DESCRIPTION

In FIG. 1 a partially unwound bag roll 1 is shown in a three-dimensional view; here it is possible to roll up the bags 2 in one another or to wind the bags 2 on a roll. The bags 2 include a front wall 3 and a back wall 4, which in this exemplified embodiment are connected with a bottom fold 5. It should be noted here that the bag 2 naturally can also be made without a bottom fold 5. The bags 2 are made of a plastic film which preferably is a thermoplastic film that has a thickness of 20 μm to 100 μm, preferably a thickness of 35 μm to 80 μm. A preferred plastic is polyethylene (PE).

Along the bottom fold 5 of the bag is a bottom seam 6, wherein in this exemplified embodiment two bottom seams 6,7 are present, one along the front wall 3 and one along the back wall 4. In the area of a bag opening 8, the bag 2 has a bag flap 9, which is formed from part of the back wall 4. By means of the bag flap 9, the bag 2 can be closed after filling, as described for example in DE 199 17 902 A1, which is incorporated herein by reference. An additional part of the back wall 4 in this exemplified embodiment is formed by the extension 10. Extension 10 is connected continuously with all bags 2, wherein the extension 10 is removably connected with the bag, preferably by a perforation 11. The bags 2 themselves are separated from one another by means of a separating seam weld 12 or a double shrink seam weld 12, wherein the side seams 13, 14 are simultaneously produced by this welding. In the area of the bag flap 9, the bags 2 are connected by a further perforation 15. If the bag flap 9 is not needed in the case of an automated bag 2, optionally a perforation 16 can be applied to the bag opening 8, so that the bag flap 9 can be removed from the bag 2.

Alternatively in accordance with the invention it is likewise conceivable that the bags 2 may be made as a half-tube, wherein during the folding of the bottom fold 5 the front wall 3 and the back wall 4 will be formed simultaneously from the half-tube. In this process the bottom fold 5 will be introduced into the half-tube in such a way that an extension 10 and a bag flap 9 are present in the form shown in FIG. 1. This would mean that the extension 10 would become double-walled. To form a bag it would be necessary only to perform one weld 7 in the bottom area of the bag 2.

In addition it is alternatively conceivable to dispense with the perforation 11, and separation of the extension could then take place during packaging by separating cuts in the automatic packager. This applies on one hand for the extension 10 and on the other for the bag flap 9. Thus it is also conceivable not only to separate the extension 10 by means of separating cuts, but also the bag flap 9 by means of separating cuts in the area of the dotted line 16 from the bag 2.

As is apparent from FIG. 1, that for rolling up the bags 2 and for conveying the bags 2 into and through a packaging machine, two retaining or winding strips 9,10 are available. Through the retaining or winding strips, the bags 2 can additionally be guided into the packaging machine very easily and with good positional accuracy. In this process, before, during or after the introduction of the product into the filling opening 8 of the bag 2, the extension 10 or the extension 10 and the bag flap 9 are separated from the bag 2.

In the solution according to the invention the finished bags 2 in the filling area 8 and in the area of the bag bottom are provided with support films 9, 10, preferably of the same material. The support films 9, 10 are pulled off by means of a perforation 11, 16 or cut off via a cut and separated from the bag 2. Consequently according to the invention it is even possible to avoid a perforation 11 in the area of the bag bottom 17 and only to introduce a perforation 15 between the bag flaps. By means of these supporting films 9, 10 the bags 2 can be rolled up and made into larger bundles 1. During the subsequent packing process in automated packaging machines or a packing machine, the supporting films 9,10 are separated from the bag 2 and disposed of, wherein the separated supporting films 9,10 can be reused by recycling.

To prepare a defined and especially a uniform bag roll 1, in FIG. 2 an example is shown for a possible folding of a bag 2 before rolling up. FIG. 2 shows the bag 2 described in detail in FIG. 1 in a folding pattern in which the bag flap 9 and part of the front wall 3 were folded via the filling opening 8. As a result, on the left-hand side of FIG. 2 and at the bag bottom 17 in the area of the bottom fold 5, there is in each case a four-layer construction, allowing for uniform rolling and thus a uniformly thick bag roll 1. In addition, naturally it is likewise possible to fold the bag flap 9 in a direction opposite the filling opening.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims. 

1. A bag comprising: a filling opening; a front wall; a back wall; and an extended back wall provided in an area of the filling opening to form a bag flap, the front wall and the back wall being welded together on their longitudinal sides to form side walls, and on a transverse side opposite the filling opening to form a bottom seam, wherein the bag has an extension projecting beyond the bottom seam and at least the bag flap is connected removably with a bag flap of an additional bag and the extension is connected continuously with the bags.
 2. The bag according to claim 1, wherein the extension is connected removably to the bags.
 3. The bag according to claim 1, wherein a side seam located between two bags is produced by separating-seam welding or double-shrink seam welding.
 4. The bag according to claim 1, wherein the bag flap is fastened via a perforation to the bag.
 5. The bag according to claim 1, wherein the bags arranged adjacent to one another are connected by a perforation.
 6. The bag according to claim 1, wherein the bag has a bottom fold.
 7. The bag according to claim 1, wherein the bag is formed from a plastic film.
 8. The bag according to claim 1, wherein the extension is connected removably to the bags via a perforation. 